1. Field of the Invention
The present invention relates to a chuck for drilling and chiseling tools and including a receiving sleeve having a central bore for receiving a tool shank and at least one through-opening formed in a sleeve wall, at least one locking member supported for a limited pivotal movement about a pivot axis, which extends substantially perpendicular to a longitudinal axis of the receiving sleeve, and projecting at least partially into the through-opening of the sleeve, with the locking member extending in its locking position, through the through-opening of the sleeve and into a receiving sleeve interior, a guide ring surrounding the receiving sleeve and at least partially overlapping the locking member from pivoting into its release position, and an actuation sleeve displaceable in a direction opposite to an operational direction of a tool against a spring-biasing force for enabling pivoting of the locking member into its release position.
2. Description of the Prior Art
A chuck of the type described above is disclosed, e.g., in German Utility Model DE-296 12 795 U1. The receiving sleeve of the disclosed chuck has a through-opening the length of which in a direction parallel to the longitudinal axis of the receiving sleeve is substantially equal to the length of the locking member measured likewise in the direction parallel to the longitudinal axis of the receiving sleeve. In order to provide for an unhindered pivotal movement of the locking member into and out of the interior of the guide ring, against which the locking member is radially supported, must be displaced, both upon the insertion and withdrawal of the working tool, in a direction opposite to the operational direction of the tool into a position enabling the unhindered pivotal movement of the locking member. The displacement of the guide ring is effected with the actuation sleeve, in which the guide ring is supported and which, to this end, is displaced in the direction opposite to the operational direction by a force applied to the actuation sleeve outside of the drilling or chiseling tool.
Because the actuation sleeve is biased into the operational direction by a compression spring, a drilling or chiseling tool operator should apply a manual force to displace the actuation sleeve against the spring-biasing force. With often replacement of the working tool, this requires a substantial expenditure of force by the operator, and the operator becomes rapidly tired.
Accordingly, an object of the present invention is to provide a chuck which would enable insertion of the working tool without first actuating the actuation sleeve. Another object of the invention is to provide a chuck the actuation sleeve of which is displaceable to a position, in which the unhindered pivotal movement of the locking member becomes possible, with a minimal expenditure of force.